Electric and hybrid vehicles have recently become a more common sight on roads worldwide. They have one thing in common and that is they all require a large and powerful rechargeable energy storage, also known as a battery. In most such batteries, several battery cells are stacked together to form a battery powerful enough to provide energy for the vehicle to drive for example several tens of kilometers. The battery cells are in most cases mechanically fixed together with a common frame or enclosure to form a single unit which is conveniently mounted in the vehicle. Furthermore, the size of a battery providing sufficient power for driving an electric or hybrid energy is relatively large, whereby the battery cells tend to be closely packed in order to reduce the size of the battery.
The high powers of the batteries constitute a high risk, in particular for passengers of the vehicle but also for the vehicle itself. For example, in case of an accident causing an impact on the battery, a short circuit may occur which may result in a fire. Therefore, a protection system of some type may be useful.
US20110250477 discloses a battery module provided with an air-bag system arranged outside the module for absorbing an impact. However the protection for the cells in the module is limited and an impact force may not be efficiently distributed in order to avoid damage to the cells.
Therefore, there is a need for improved protection for battery cells arranged in a battery module of an electric or hybrid vehicle.